Question: $ { \left[\begin{array}{rr}{1} & {4} \\ {2} & {0} \\ {2} & {0}\end{array}\right]-\left[\begin{array}{rr}{-2} & {4} \\ {-1} & {2} \\ {0} & {-1}\end{array}\right] = {?} } $
Solution: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{1}-{-2} & {4}-{4} \\ {2}-{-1} & {0}-{2} \\ {2}-{0} & {0}-{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{3} & {0} \\ {3} & {-2} \\ {2} & {1}\end{array}\right]}$